NATURAL THEOLOGY. 115 



t>ne general mass of substance spread over the bones, 

 it is, in fact, composed of five hundred and twenty- 

 seven separate strips of different sizes and shapes ; 

 and each of these is what is termed a muscle. They 

 play freely over one another, and have a fatty matter 

 between, which renders their motions easy. If the 

 whole flesh of the body was dissected, as it would nat- 

 urally separate, it would come apart in these five hun- 

 dred and twenty seven strips, as smooth and as clean 

 as so many straps of gum elastic. Each of them 

 may be termed a rope to produce some particular mo- 

 tion. The middle is fleshy and red, and usually 

 takes the name of the muscle. This portion is al- 

 ways the largest ; then it goes on diminishing in size 

 towards each extremity, where it terminates in a white 

 leathery string or strap, which is called the tendon. 

 Every muscle, with a few exceptions, is fastened 

 between two different bones, going from one to the 

 other ; and the object is, to pull the bones together, or 

 to draw them in any direction which the pulling would 

 give them. Thus are all the motions of the bones 

 performed. If we tie a strap of gum elastic to our 

 thumb and finger, and spread them open so as to ex- 

 tend the strap ,J;lie force it will exert to draw them 

 together, may give us a very tolerable idea of the 

 action of a muscle upon the bones to which it is at- 

 tached. 



T. As the muscle, however, is not found to be 

 any thing like gum elastic, what makes it contract so 

 as to pull upon the bones ? 



A. The middle or fleshy part has the power of 

 shortening itself at our will ; and in some instances 



